Capalictus, a new subgenus of Lasioglossum Curtis, 1833 from South Africa, with description of three new species (Hymenoptera, Apoidea, Halictidae)

1 Royal Belgian Institute of Natural Sciences, Department of Entomology, Rue Vautier 29, B-1000 Brussels, Belgium. Corresponding author, Email: alain.pauly@brutele.be 2 Cornell University, Department of Entomology, 3119 Comstock Hall, Ithaca, NY, USA, 14853. Email: jason.gibbs@cornell.edu 3 The Natural History Museum, Department of Entomology, Cromwell Road, London, SW7 5BD, UK. Email: m.kuhlmann@nhm.ac.uk


Introduction
We describe a new subgenus of Lasioglossum, endemic to the Cape Province of South Africa.This new subgenus was first described as a new species-group of Sellalictus Pauly, 1980 by Pauly et al. (2008), based on a single new species, "Evylaeus (Sellalictus) fynbosensis Pauly, Timmermann & Kuhlmann, 2008".Discovery of at least three new species belonging to the same species-group as L. fynbosense (comb. nov.) in combination with recent molecular phylogenetic results (Gibbs et al. 2012) incline us to describe this group rather as a distinct subgenus.A recent molecular phylogeny of halictid bees demonstrated with strong support, that this group composes a basal clade of the Hemihalictus series (Gibbs et al. 2012).This position on the phylogenetic tree strongly supports subgeneric status for these species.

Terminology
Terminology for morphological characters follows Engel (2001) and Michener (2007).Terminology for the 'propodeum' and 'metapostnotum' follows Gibbs (2011).We used the glossary of Harris (1979) for description of the surface sculpture (except "shagreened" used here in the sense of "dull due to the presence of microsculpture").Puncture density is given in terms of relationship between puncture diameter (d) and the spaces between them (i), such as i>d.Hair length is given in relative units based on the median ocellar diameter (OD).Metasomal sterna and terga, and flagellomeres are abbreviated S, T, and F, respectively, followed by the appropriate number.The following abbreviations are used throughout: upper interocular distance (UOD), lower interocular distance (LOD), ratio of mesoscutellum and metapostnotum lengths (MMR).

Measurements
Measurements were taken on enlarged pictures or directly using an ocular micrometer.

Collections
Material is preserved in the following collections: BMNH = The Natural History Museum, London, United Kingdom CUIC = Cornell University Insect Collection, Ithaca, USA RBINS = Royal Belgian Institute of Natural Sciences, Brussels, Belgium SANC = South African National Collection of Insects, Pretoria, South Africa No collection numbers are allocated to specimens.

DNA analysis
DNA was extracted and amplified following protocols explained elsewhere (Danforth 1999;Danforth et al. 2003Danforth et al. , 2004) ) from five specimens belonging to the new subgenus described below as part of ongoing studies of the phylogenetic relationships of halictid bees (Gibbs et al. 2012;Gibbs unpublished data.).
Fragments of three nuclear genes were sequenced in both directions (elongation factor-1 alpha: ef-1α, wingless: wnt-1, and long-wavelength rhodopsin: opsin) using Big Dye Terminator for the sequencing reaction.Sequencing was performed at the Cornell University Life Sciences Core Laboratories Center using Applied Biosystems Automated 3730 DNA analyzers.Sequences were assembled using Sequencher (GeneCodes).

Description
Capalictus is distinct from other African subgenera of the Hemihalictus series by the combination of following characters: small size (length 6-7.5 mm).Body black, non-metallic, metasoma red in some species (this red colouration is unique in African subgenera of the Hemihalictus series, with the exception of the kleptoparasitic L. ereptor).Metasomal terga without patches of tomentum.Mesoscutum smoothshiny, without tessellate surface.Lower paraocular area shiny and sparsely punctate.Propodeum posterior surface weakly carinate in females, not carinate in males.The carina in females not extending medially across upper margin (Fig. 1F).Clypeus and mandibles of males black.Inner metatibial spur in females with about five short teeth, the one in males without teeth.Gonocoxite of males without retrorse lobe, gonostyli pointed, half as long as gonocoxite (Fig. 15).Apex of marginal cell pointed, ending on wing margin (Fig. 1C, E).

Differential diagnosis
The new South-African subgenus Capalictus belongs to the Hemihalictus series (sensu Michener 2007) of the genus Lasioglossum Curtis, 1833, which is characterized by weak cross-submarginal veins 1rsm and 2rs-m of forewing (Fig. 1C-E).Capalictus is morphologically close to the Holarctic subgenera Evylaeus Robertson, 1902and Dialictus Robertson, 1902, and to the African subgenera Sellalictus Pauly, 1980and Afrodialictus Pauly, 1984(see classification of Pauly 1999).From Sellalictus it differs by the absence of a patch of tomentum on the metasomal terga (males of Sellalictus bear a very characteristic large patch of tomentum on base of tergum 2 while females have small baso-lateral spots of tomentum on T2-T4).Capalictus also differs by the apex of the marginal cell close to wing margin (Fig. 1C-E) (in Sellalictus the apex of the marginal cell is minutely separated from the wing margin and minutely appendiculate as in Fig. 1D).From Afrodialictus, the new subgenus differs by the lack of microtessellate texture on the body (microtessellate surface sculpture is characteristic on head, mesoscutum and propodeum of Afrodialictus; in Capalictus, mesoscutum is polished and shiny), lower part of paraocular area shiny and with some punctation (Fig. 1A) (with Afrodialictus the lower parts of the paraocular area has a different dull, frosted-like and completely impunctate surface as in Fig. 1B) and posterior face of propodeum with a very weak carina in the female (Fig. 1F) (carina entirely lacking in Afrodialictus).Capalictus can be separated from the African subgenus Mediocralictus Pauly, 1984 by the inner metatibial spur of the males without teeth (pectinate in males of Mediocralictus).Females of Mediocralictus can be separated by the peculiar shape of the propodeal carina (Pauly et al. 2001: 121, fig. 36).Capalictus can be separated from most Palaearctic species of the Hemihalictus series by the gonocoxites of males without retrorse lobe.Palaearctic Evylaeus lacking a retrorse lobe can be easily distinguished from Capalictus by the carinate propodeum (male Capalictus lack distinct propodeal carinae) and metasomal sterna with very sparse, and short setae (≤OD) (sternal hairs sometimes long (2-2.5 OD) and plumose in Capalictus).

Etymology
The specific epithet refers to the Hantam Mountains near Calvinia where the species was first discovered.Colouration.Head and mesosoma black.Metasomal terga black with apical rim translucent strawcoloured.Clypeus and mandibles completely black.Flagellum with ventral surface black.Wing membrane subhyaline, venation, pterostigma and tegula brown.Legs black except femoral apices and tibial bases brown and all tarsi pale yellow.
struCture.Head nearly as long as wide (length/width ratio = 0.91).Eyes slightly convergent below (UOD/LOD ratio = 1.09).Vertex short.Gena as wide as eye.Inner metatibial spur with five short teeth.Metapostnotum moderately long (MMR = 1.25).Propodeum with very weak lateral and oblique carinae curved to the middle of the posterior surface.

Diagnosis
♂. Close to L. hantamense but all tibiae (except a dark central maculation on tibiae II and III), tarsi, apical margins of terga and sterna yellowish orange (Fig. 12D).Mid and hind tarsi black in L. mosselinum and L. timmermanni punctate in middle of disc as on apical margin (Fig. 7D), punctation of mesoscutum denser (Fig. 7B).Differs from L. mosselinum and L. timmermanni by the largely black metasoma.

Etymology
The name refers to the distinctive yellow-orange banding of the male metasoma which is striped like a tiger.
PuBesCenCe.Greyish white and sparse.Apical rim of T2-T4 with sparse fringes.surFaCe sCulPture.Clypeus shiny with large and sparse punctures.Supraclypeal area shiny with fine punctures.Frons dull and finely rugulose, with velvet-like appearance.Upper paraocular area and ocellocular area finely and densely punctate, semi-dull.Lower paraocular area shining and sparsely punctate.Vertex shagreened.Gena finely and densely strigose-punctate.Mesoscutum smooth and shining with sparse punctures (i = 1-2d), punctures denser anteriorly and laterally of parapsidal line (i = d) with minute contiguous punctures.Preepisternum, and mesepisternum dull matt, minutely and densely roughened.Hypoepimeral area and metepisternum minutely and densely punctate.Metapostnotum with weak anastomosing rugae extending no more than 2/3 distance to posterior margin.Lateral surface of propodeum minutely roughened and shagreened.T1 smooth and distinctly punctate in middle of disc as well as on apical margin (i = 1.5d), smooth and impunctate anteriorly and laterally.T2 punctate in middle of disc as on apical margin.T3-T4 with sparse punctures.

Female
Close to L. mosselinum but metasoma with more extensive red colouration on last tergum (Fig. 16F), base of first tergum often black (metasomal terga black with pale apical margins in L. hantamense and L. tigrinum).Rugae of metapostnotum are finer and shorter than in L. mosselinum, dorso-lateral slopes of propodeum with microtessellate dull surface, not shiny as in L. mosselinum (Fig. 9C-D).
PuBesCenCe.Greyish white and sparse.Metasomal terga without patches of tomentum.surFaCe sCulPture.Clypeus shiny with large and sparse punctures.Supraclypeal area shiny with fine punctures.Frons dull and finely rugulose, with velvet-like appearance.Paraocular area and ocellocular area finely and densely punctate, semi-dull.Lower paraocular area shining and sparsely punctate.Vertex shagreened.Gena finely and densely strigose-punctate.Mesoscutum smooth and shining with sparse punctures (i = 2-3d), punctures denser anteriorly and laterally to parapsidal line (i = d).Mesoscutellum more finely and densely punctate, shiny medially Metanotum dull matt with minute contiguous punctures.Preepisternum, and mesepisternum dull matt, minutely and densely roughened.Hypoepimeral area and metepisternum minutely and densely punctate.Metapostnotum with weak anastomosing rugae extending no more than 2/3 distance to posterior margin.Lateral surface of propodeum minutely roughened and shagreened.T1 smooth and nearly impunctate on disc, apical margin finely punctate (i = 1.5d).T2 punctate on basis and apical margin, not in the middle.T3-T4 with very sparse punctures.
ProPodeum.It is with very weak lateral and oblique carina curved to the middle of the posterior surface.

Additional material
The following specimens are identified as Capalictus, but not described as new because only a single sex is known.They differ slightly from the species above by the punctation of mesoscutum and metasomal terga.The information is provided to encourage and facilitate future study of the subgenus.Specimens from Hermanus (4 ♀♀ including Voucher 01-54) are similar in size and colour to L. tigrinum sp.nov., but their tergum 1 is nearly impunctate on the disc, punctures of the mesoscutum are larger and sparser, punctures on the face are stronger.
Specimens with black metasoma from Kunje Farm (2 ♀♀) and Betty's Bay (1 ♀) are similar in size and colour to L. hantamense sp.nov.but punctures of the mesoscutum are stronger.